<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
    <style>
        div{
            background-color: orange;
            width: 100px;
            height: 50px;

        }
        /*鼠标悬停样式*/
        div:hover{
            background-color: greenyellow;
            width: 100px;
            height: 100px;
        }

        input:focus{
            outline: none;
            width: 200px;
            height: 100px;
            border:5px double purple ;

        }
    </style>


</body>
    <div>11111</div>
    <p></p>
    <input>

</html>